OPEXIA OP-DW02, wireless door & window sensor works perfectly with OPEXIA alarm system. Some of the conveniences of this device are: easy installation, practical usage and trustworthy signal transmittance. It is easy to expand OPEXIA alarm system with OP-DW02 just by yourself. This device is for indoor doors and windows use mainly. With high precision manufacturing, inner antenna and an anti-tamper switch system makes its more stable and accurate.Once the door or window is opened, the OPEXIA OP-DW02 main unit will be separated from the magnet bar. At the meanwhile, wireless alarm signal is activated and sent to the main panel.